Flexible and rigid tubing may have formed ends for use in coupling the tube to a fitting or to another tube. Flexible tubing may, for example, have flared ends to be joined to a flexible or rigid tube or fitting. A flared tube may be joined with a bushing and/or a nut, to connect to the tube or fitting. The inner diameter of the flare may be sized to accept and be joined to the outer diameter of a tube or fitting. The end of rigid tubing may be formed into a flare or flange. U.S. Pat. No. 7,604,472 B2, hereinafter the '472 patent, describes a method and apparatus for forming flared tube ends, the entire contents of which are incorporated herein by this reference.
Various types of plastic pipe and tube assemblies may be employed in fluid flow applications. The assemblies may for example be manifold assemblies, with an input port connecting to several output ports. Each of the ports may have tube or pipe fittings to allow the ports to be connected in a fluid system. The assemblies can have many ports, and reduction in footprint or size of the assemblies is desirable. U.S. Pat. No. 8,372,235, the entire contents of which are incorporated herein by this reference, illustrates exemplary assemblies of plastic parts. Exemplary fluid flow applications include those in the pharmaceutical and semiconductor fabrication industries, where different fluids are passed through complex fluid flow paths. Minimizing leaks in such fluid flow applications and installations can be a problem. The use of systems as describe in the '472 patent to form flared tube ends of high quality and dimensional stability has significantly addressed the problem of leaks in fluid flow applications utilizing flared tubing and associated fittings. However, the use of closely packed fittings in installations increases the difficulty of accessing the individual fittings to tighten connections, and thus presenting a risk of leakage.